Internal combustion engine control



July 26, 1938. L. c. cox ETAL 2,125,066

I INTERNAL COMBUSTION ENGINE CONTROL Filed April 1, 1957 19 Z! M N" 27 O INVENTOR.

.Sauzs Charle-s g ac BY I 1111 Qa-rtst ATTORNEY.

Patented July 26, 1938 2,125,066 INTERNAL COIWBU STION ENGINE CONTROL Louis Charles Brightwaters, and John Cariei,

Jamaica, N. Y., assignors to Federal Aircraft Corporation, Lindenhurst, N. Y., a corporation of New York Application April 1, 1937, Serial No. 134,270

6 Claims. (or. 123-193) efficient and reliable operation for affecting asafe take-oil.

Other objects and features of the invention will become more apparent from the following description taken with reference to the accompanying drawing forming part of the specification and wherein;

Figure 1 is a diagram showing a control arrangement and apparatus in accordance with the invention, and

Figure 2 is a partial view of Figure 1 illustrating a modification of the invention. Y

As is well known, it is necessary for an airplane engine to be warmed up to the proper operating temperature'to insure efficient and reliable operation before a safe take-off of a plane may be effected. A cold engine fails to readily volatilize the gasoline mixture due tolack of heat. This may result in ignition failures in one or more cylinders, poor lubrication with consequent overheating and destruction of bearings, and other well known defects causing the engine to miss or cease firing altogether and to quit finallyQ In many cases the result may be disastrous. Pilots are therefore usually instructed to warm up the engine to the temperature recommended by the manufacturer before attempting a take-off. However, it often happens that these instructions are overlooked or violated, such as when the pilot is in a great hurry and decides to venture a takeoff with a cool or insufficiently warmed-up engine, with the result in many cases of serious accidents and loss of life and material.

By the present invention this danger and possibility due to error or sheer violation of given rules is substantially eliminated in a most simple and efficient manner.

A preferred method of this invention consists in limiting the movement of the throttle of the engine beyond a predetermined point until its temperature has reached the proper operating value at which a safe and reliable take-off may be effected.

A system of this type is illustrated diagrammatically in Figure 1 wherein parts not necessary for an understanding of the invention have been omitted to simplify the disclosure. There is shown at a conventional throttle lever for controlling the amount of gas supplied to the engine manifold when moved towards the right in the example illustrated. Before starting the engine, the electric ignition circuit is closed in a known manner by closing the so-called ignition switch. The engine may then be started and the throttle lever moved to a predetermined point determined by a blocking element or collar i2 engaging the upper part of a plunger 53 held in its upper position by a coil spring i4 and arranged to be pulled into a normally deenergized magnet core or solenoid l5 upon energization of the latter. The element I! in the example shown is slidably mounted upon a rod or extension I6 connected with the lever Ill and arranged to move in its lengthwise direction when the throttle lever is moved'towards the right and the throttle or valve l6 arranged intermediate the carbureter I7 and the engine 25 and admitting the gas mixture to the engine is opened as indicated in the dottedposition in the drawing. The element I2 is fixed in any desired position, such as bya set screw or the like.

The entire control apparatus is preferably enclosed in a sealed metal box l'l so that no one can tamper with it without breaking the seal IS. The electric energizing circuit for the solenoid is completed through a switch ii, a source of current such as a battery l9 and a pair of contacts and 2i of a thermostatic or heat-responsive device of suitable construction which in the example shown comprises a tube 22 0f glass or other insulating material connected with a casing or bulb 23 through a tube 24 which latter may be rigid or flexible for mounting the device in any convenient position. The switch ll may be either separate or is preferably combined with the ignition switch ll so that both switches are connected and disconnected simultaneously. The bulb 23 of glass or other insulating material suitably mounted in a metal housing is secured to the engine 25 in close proximity to the cylinder and is filled with mercury or any other suitable conducting fluid.

The operation of the arrangement as described is as follows: I

Under normal conditions; that is, when the engine ii is at rest and in a cold state, the mercury column will extend to a certain length within the tube 22 and the contacts 20 and iii will interrupt the circuit for the solenoid. As a result, the plunger i3 is pulled in a downward direction against the action of the spring it thereby releasing the blocking mechanism and allowing the pilot to move the throttle lever as he desires up to full throttle opening and affect a safe take-off. In this position an indicator 26 which may be a coloreddisc or ball as shown will project through the metal housing thereby apprising the pilot that the mechanism is in working order. Should the mechanism have become defective and be prevented from proper functioning, the indicator 26 will not appear, thereby authorizing the pilot to break the seal I 8, remove the bottom cover casing I], and pull down the ball 26. The latter may be locked such as by twisting in the manner in as described in Fig. 1. H up the freeextension of the bi-metallic element 21 will bend in a downward direction with proper of a bayonet catch thereby keeping the plunger in its lower position and permitting a throttle to be used as usual.

. After the engine has been brought to rest by moving the lever III to the extreme left position and the temperature has decreased below the.

critical point required for safe operation, the

-mercury column in the tube 22 will descend thereby interrupting contacts 2| and 22 and in turn deenergizlng the solenoid 15. As a result, the plunger will be pulled in an upward direction to the position illustrated by the action of spring l1 and-the system restored to a condition for renewed operation. i

In place of a thermostatic device of the type described comprising a mercury column, any equivalent heat-responsiveelectrical device may be used for the purpose of the invention, such as a bi-metallic element as illustrated in greater detail in Fig. 2 of the drawing. The lattercomprises a bi-metallic strip 21 wound into a spiral having one end fixed and having its other end tree and extended in a straight line and carrying a contact 21. The latter is arranged to co-- 'operate with a stationary contact 28 and the; entire device is mounted in a metal casing 28 secured to an appropriate part of the engine cylinder similar as in the case of Fig. l. The contacts 21 and 28 are connected in a solenoid circuit. and the operation of this device is simi arrangement oi the bi-metallic strip thereby closing the contacts 21 and 28 and releasing the throttle of the engine at a definite temperature similarly as described hereinabove.

As is obvious, the invention is not limited to airplane engines but applies with equal advantage to internal combustion engines for any other use where it is desirable to prevent the engine from being subjected to a load beyond a' predetermined point before reaching a safe and proper operating temperature.

It will be further understood from the above that the invention is not limited to the specific arrangement of elements and parts as described herein for illustration and that the underlying inventive thought is susceptible of numerous modiflcatioris'and variations coming within the broad scope and spirit of the invention as defined in the appended claims.

We claim:

1. The combination with an internal combos tion engine having throttle means for controlling the power output thereof, of a thermostatic device arranged to be responsive to the engine temperature, said thermostatic device having a pair of cooperating contacts, a source of electric current, an electrically actuatable blocking means normally restraining said throttle to be moved beyond a predetermined point, said blocking means, said source, and said contacts forming a control circuit, whereby with increase of the engine temperature beyond a predetermined value said blocking means is released to unlock said throttle means.

2. In combination with an internal combustion As the motor warms aisaoeo' engine, power output control means for said engine, thermostatic means responsive to the enginettemperature, means for restraining the operation oi said control means to a predetermined iraction of the full power output of the engine, a control circuit for said thermostatic control means, and further means for releasing and applying said restraining means actuatable by said control circuit when the engine temperature increases above or decreases below a predetermined value, respectively.

3. In combination with an internal combustion engine, throttle control means for said engine, a thermostatic device responsive to the engine temperature, an electric control circuit therefor, a locking member engaging said' throttle and preventing its opening beyond a predetermined point, a current-responsive device arranged to be energized by said control circuit and adapted to unlock said member upon increase of the engine temperature beyond a -predetermined value, and means for returning said member to its locking position upon deenergization of said current responsive device.

4. In combination with an internal combustion engine, a throttle control device, a thermostatic device responsive to the engine temperature, an electric control circuit therefor, a plunger arranged to normally engage said control device to limitthe throttle opening beyond a predetermined point, and a solenoid connected in said circuit and arranged to attract said plunger to unlock the throttle upon energization of said solenoid upon closing of said control circult by said thermostatic device when the engine temperature reaches a predetermined value.

5. In combination with an internal combustion engine, a throttle control device, a thermostatic device responsive to the engine temperature, a control circuit therefor, a plunger arranged to normally engage said control device to prevent opening of the throttle beyond a predetermined point, a solenoid adapted to be energized by said circuit and arranged to attract said plunger to unlock said control device when the engine temperature increases beyond a predetermined value, and resilient means counteracting the movement -of said plunger and adapted to return said plung er to normal locking position after the throttle has been closed and the engine temperature decreased beyond said predetermined value.

6. In combination with an internal combustion engine, an ignition circuit for said engine, throttle control means for said engine, a thermostatic device responsive to the engine temperature, an electric control circuit therefor, a locking element engaging said throttle control means to normally prevent the opening of the throttle beyond a predetermined limit, a current responsive device arranged to be energized by said control circuit and adapted to unlock said element upon increase of the engine temperature beyond a predetermined limit value, a switch for said ignition circuit, and a further switch mechanically coupled with said last switch for closing and opening said control circuit simultaneously with the closing and opening of the ignition circuit.

LOUIS CHARLES cox. JOHN CARISI. 

